/*
 * Copyright (c) 2017 Boucher, Antoni <bouanto@zoho.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

use std::cell::Cell;
use std::char;
use std::rc::Rc;

use gdk::EventKey;
use gdk::enums::key::Escape;
use gtk::Inhibit;
use mg_settings::{
    self,
    EnumFromStr,
    EnumMetaData,
    SettingCompletion,
    SpecialCommand,
};

use app::{Mg, Mode};
use app::ActivationType::Current;
use app::Msg::{self, EnterNormalModeAndReset};

impl<COMM, SETT> Mg<COMM, SETT>
    where COMM: Clone + EnumFromStr + EnumMetaData + SpecialCommand + 'static,
          SETT: Default + EnumMetaData + mg_settings::settings::Settings + SettingCompletion + 'static,
{
    /// Handle the key press event for the command mode.
    #[allow(non_upper_case_globals)]
    fn command_key_press(&mut self, key: &EventKey) -> Option<Msg<COMM, SETT>> {
        match key.get_keyval() {
            Escape => Some(EnterNormalModeAndReset),
            _ => self.handle_shortcut(key),
        }
    }

    /// Handle the key release event for the command mode.
    fn command_key_release(&mut self, _key: &EventKey) -> Option<Msg<COMM, SETT>> {
        if !self.is_normal_command() && COMM::is_incremental(self.model.current_command_mode) {
            let command = self.model.status_bar_command.clone(); // TODO: remove this useless clone.
            let msg = self.handle_special_command(Current, &command);
            return msg;
        }
        None
    }

    /// Check if the key should be inhibitted for the command mode.
    #[allow(non_upper_case_globals)]
    fn inhibit_command_key_press(current_mode: &Rc<Cell<Mode>>, key: &EventKey) -> Inhibit {
        match key.get_keyval() {
            Escape => Inhibit(false),
            _ => Self::inhibit_handle_shortcut(current_mode, key),
        }
    }

    /// Check if the key should be inhibitted for the input mode.
    #[allow(non_upper_case_globals)]
    fn inhibit_input_key_press(current_mode: &Rc<Cell<Mode>>, key: &EventKey) -> Inhibit {
        match key.get_keyval() {
            Escape => Inhibit(false),
            _ => Self::inhibit_handle_shortcut(current_mode, key),
        }
    }

    /// Check if the key should be inhibitted.
    pub fn inhibit_key_press(current_mode: &Rc<Cell<Mode>>, key: &EventKey) -> Inhibit {
        match current_mode.get() {
            Mode::Normal => Self::inhibit_normal_key_press(current_mode, key),
            Mode::Command => Self::inhibit_command_key_press(current_mode, key),
            Mode::BlockingInput | Mode::Input => Self::inhibit_input_key_press(current_mode, key),
            _ => Self::inhibit_handle_shortcut(current_mode, key)
        }
    }

    /// Handle the key press event for the input mode.
    #[allow(non_upper_case_globals)]
    fn input_key_press(&mut self, key: &EventKey) -> Option<Msg<COMM, SETT>> {
        match key.get_keyval() {
            Escape => {
                if let Some(callback) = self.model.input_callback.take() {
                    callback(None, self.model.shortcut_pressed);
                }
                Some(EnterNormalModeAndReset)
            },
            keyval => {
                if self.handle_input_shortcut(key) {
                    return None;
                }
                else if let Some(character) = char::from_u32(keyval) {
                    if self.model.choices.contains(&character) {
                        self.set_dialog_answer(&character.to_string());
                        return None;
                    }
                }
                self.handle_shortcut(key)
            },
        }
    }

    /// Handle the key press event.
    pub fn key_press(&mut self, key: &EventKey) {
        let msg =
            match self.model.current_mode.get() {
                Mode::Normal => self.normal_key_press(key),
                Mode::Command => self.command_key_press(key),
                Mode::BlockingInput | Mode::Input => self.input_key_press(key),
                _ => self.handle_shortcut(key)
            };
        if let Some(msg) = msg {
            self.model.relm.stream().emit(msg);
        }
    }

    /// Handle the key release event.
    pub fn key_release(&mut self, key: &EventKey) {
        let msg =
            match self.model.current_mode.get() {
                Mode::Command => self.command_key_release(key),
                _ => None,
            };
        if let Some(msg) = msg {
            self.model.relm.stream().emit(msg);
        }
    }
}